Aug 16, 2015

How the Natural World has Helped Influence Culture and Society

Biophiles (lovers of life, to save you googling) around the world may relish the sights, smells and sounds that nature provides us, but many of us probably take for granted just how profoundly some aspects of the natural world have impacted our culture and society throughout history.

To showcase some of the weird and wonderful ways nature has influenced the human race, the London Natural History Museum has teamed up with BBC Radio 4 to produce a fantastical series for your learning pleasure. IFLScience has been picking at some of the museum’s brilliant brains to give you a snippet of some of the awesome examples to come, and here they are:

How Brambles Help Forensic Investigations

Starting off on a rather grim topic, but did you know that brambles, those prickly shrubs that bring to us delicious blackberries and raspberries, can be used to help murder enquiries or suspicious death cases? Yep. Provided, of course, that the body ends up outside, these scrambling vines can help determine how long it’s been there, as they have a tendency to “grow in areas where people do bad things to other people, like railway sides or shrub lands,” Dr. Mark Spencer, British and Irish Herbarium senior curator, told IFLScience.

“If, for example, someone is murdered or dies, and their remains aren’t discovered relatively quickly, they can be taken within the landscape quite quickly by plants.” And if the skeletal remains of the corpse are still there a few years on, brambles and other vegetation growing in the area can provide a useful calibrator to assess how long someone has been in the landscape, he adds. A more traditional way to identify a body, which could then help date it, would be to use dentition, but over time these can become damaged and sometimes teeth are absent altogether.

So how do scientists use these shrubs? Brambles are highly organized plants; on average, an individual plant will send out one or two arching vegetative growths annually, increasing the size and territory of the bramble. The following year, these stems will again produce side shoots, and it is this repetitive annual growth pattern that can help inform detectives of how long a body has been there. So if a body is underneath or interspersed among brambles, the interplay between the number of stems and the remains can serve as a useful indicator for scientists.

This cost-effective technique therefore helps the police narrow down dates, but it is not used in isolation. Rather, scientists will take information from whole plant communities—brambles just happen to be widespread in the UK.

Corepics VOF/ Shutterstock

Willy Wonka’s Never-Fading Paint, Thanks to Butterflies

Nature provides us with some awesome colors, from brilliant blues and fiery reds to emerald greens and passionate pinks. But not all of these are the result of pigments; some are the result of the interaction between light and microscopic surface nanostructures. These so-called structural colors tend to be brighter and more vivid than those that arise from pigmentation, and include the shimmering shades we see on butterfly wings and some bird feathers.

Agrus/ Shutterstock

Aside from the dazzling beauty structural coloration can create, why are scientists interested in it? Remarkably, the NHM’s Professor Andrew Parker tells IFLScience that some 50-million-year-old insects that display structural coloration have retained their iridescence, leading scientists to believe that if they can replicate it, they could produce colored products like paint that won’t fade.

“If you learn the principles behind nature’s colors you can start to produce any color you want—something bright, flashy, or even something that can change color depending on the angle you view it from,” said Parker.

To discover the secret behind the shimmering wings of butterflies, Parker’s team first took cells from the part of a chrysalis that goes on to become a wing and started culturing them in petri dishes. By observing how the scales form in the lab, the scientists can see how the tiny structures that produce color develop over time, with the overall goal of emulating that process. The end product would be tiny flakes, etched with structures that produce colors of desire, that will be mixed with a transparent medium.

Interestingly, the butterfly scales arise under ambient temperatures and low pressures, but when scientists try to make these dainty structures themselves, high temperatures and pressures are required. However, if scientists can pinpoint the suite of conditions that cells require in nature, then they may be able to run the process without the need for huge amounts of energy, or the toxic mix of chemicals usually required to produce paint. And as an added bonus, paint made using this technique would also biodegrade faster than traditional paints, Parker says.

Nikola Rahme/ Shutterstock

How Insects Have Influenced Technology

It’s not just butterflies that scientists are keen to learn from; a tiny, humble-looking beetle found scurrying across southern Africa’s parched Namib Desert is helping scientists provide water to communities in need.

Although a moist fog blows across this desert’s sandy dunes, the tiny water droplets contained within aren’t heavy enough to fall to the ground as rain, thus most thirsty animals won’t benefit from it. But the Namib beetle sports a unique, bumpy shell with both hydrophobic (water-hating) and hydrophilic (water-loving) points that act as a “seeding point,” instantly growing droplets until they are large and heavy enough to roll towards the insect’s mouth—with the help of a little headstand—and quench its thirst.

Ch.Gerber/ Shutterstock

Parker’s team has been endeavoring to copy this little bug in order to produce a simple, fog-harvesting net that could bring water to both remote villages and hospitals located in arid areas. Working with the Massachusetts Institute of Technology, they have come up with a cheap and simple material that can be printed using special hydrophilic inks on a hydrophobic surface, or vice versa, Parker tells IFLScience. Tests are currently underway in Chile’s Atacama Desert, and it’s already proving to be a success.

But these aren’t the only two pies Parker has his fingers in: His team is also copying the anti-reflector design found on a 45-million-year-old fly eye, which sports a special grating that prevents light reflecting from the surface. Using the eye as a basis for design, they have managed to produce sticky plastic sheets that can be adhered to solar panels, which resulted in an impressive 10% increase in energy capture due to the reduction in reflection.

The NHM is proud to be home to over 200,000 clutches of eggs, all of which come with information on when and where they were found and to which species they belong. This mega-archive has been built up over the past 250 years and, with more than 5,000 species, represents well over 50% of the world’s bird species.

But these don’t just sit there looking pretty; they’re a “3D biological library, ready to be investigated if a question arises,” Douglas Russell, NHM senior curator of birds, tells IFLScience. So what kind of questions are we talking about? Around half a century ago, British naturalist Derek Ratcliffe began to use this collection for his pioneering work on the effects of certain pesticides, like DDT, on birds of prey.

After noticing that peregrines and other species often had broken eggs in their nests and abnormally small clutches, Ratcliffe began examining the collection of egg shells. He discovered that those gathered after the late 1940s had experienced thinning, a time that coincided with the introduction of DDT. Others began replicating his work in other regions, and the evidence for the role of DDT in shell thinning became so convincing, as highlighted in the graph below, that pressure to ban these chemicals eventually led to their progressive phase out over the next 25 years.

D. Ratcliffe, 1970.

Even though we have learned our lesson about DDT and other so-called organo-chloride pesticides, thanks to this pioneering work, scientists today can still use this ever-growing collection to answer other questions, for example how climate change affects breeding trends. Although they can’t tell us how something is causing these changes, Russell says that they can act as a motivator to understand the driving forces. “It’s the beginning of a story, not the end,” he adds.

Syrian Ostrich Egg, courtesy of the Natural History Museum

From Witches to Harry Potter: Myths and Medicines of Mandrakes

Mandrakes have been used medicinally for centuries, but these plants also have a lot of mythology associated with them. If you’re a fan of Harry Potter, you may recall them being used in a Herbology class in which the students had to repot them using earmuffs to prevent their deathly screams from being heard. This story is actually rooted in traditional belief about these plants, Dr. Sandy Knapp, merit researcher of the NHM’s Life Sciences Plants Division, tells IFLScience.

Mandrake, courtesy of Sandra Knapp

These plants appear in 16th-century (Age of Enlightenment) herbals, used medicinally for all kinds of things, such as sedatives or anesthetics. They were therefore highly sought after in their native Mediterranean habitat and efforts were required to protect them from theft, which is thought to have contributed to one of the main myths associated with them.

It was believed that the extensive mandrake roots were inhabited by a demon, likely also fueled by their bizarre resemblance to a human figure, which would possess and kill whoever uprooted them. This necessitated some careful gardening: In order to remove them from the ground, you had to dig around them and then tie your dog to the roots, which would then run away and pull out the plant (apparently the dog was impervious to the demon…).

Mandrake, from De Materia Medica. Courtesy of the Natural History Museum.

Mandrakes belong to the nightshade family, which contains many staples that we eat—such as tomatoes and aubergines—but also slightly less edible things like deadly nightshade and tobacco. Some members of this family produce toxic, ring structure compounds called tropane alkaloids that can be potent hallucinogens. They can be absorbed through mucous membranes on the body and often bestow the sensation of flying, which is why they have been associated with witches’ broomsticks. Many 15th-century paintings depict witches gallivanting around on their brooms, naked, and it was written that this is how they would apply the ground up plants to their bodies, allowing the chemicals to soak up through their … areas… Lovely.

So there you go, a truly diverse collection of examples of how the natural world has influenced the society we live in.

If you’re keen to find out more, the series continues on 09 June at 11:00 BST, with this week’s fascinating topic being sharks. You can listen to it here.